9867721 has 2 divisors, whose sum is σ = 9867722. Its totient is φ = 9867720.

The previous prime is 9867677. The next prime is 9867731. The reversal of 9867721 is 1277689.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9853321 + 14400 = 3139^2 + 120^2 .

It is a cyclic number.

It is not a de Polignac number, because 9867721 - 2¹⁵ = 9834953 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9867731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4933860 + 4933861.

It is an arithmetic number, because the mean of its divisors is an integer number (4933861).

Almost surely, 2^9867721 is an apocalyptic number.

It is an amenable number.

9867721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9867721 is an equidigital number, since it uses as much as digits as its factorization.

9867721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 42336, while the sum is 40.

The square root of 9867721 is about 3141.2928866949. The cubic root of 9867721 is about 214.4892944235.

The spelling of 9867721 in words is "nine million, eight hundred sixty-seven thousand, seven hundred twenty-one".